Monday, November 28, 2011

Thanksgiving in Greenport NY

Families join to celebrate Thanksgiving in Greenport NY.
Left to right: Stuart, Terese, Jonathan, Kit, Frank, Seanna, Katy, Felix, Steve
Surnames: Bull, Hollingsworth, Hunt, Svoboda
On a leash: Dixie
Background: Mitchell Park Carousel

Monday, November 21, 2011

My donation to your re-election campaign

Following today's outcome of the Joint Select Committee on Deficit Reduction, I sent the following email message to ALL the committee members.

[Message begins]
I am an independent voter in New York. I do not make donations to one party over another. I support the various campaigns of elected officials across the USA by individual donations. I am so disappointed by the results of the Joint Select Committee on Deficit Reduction that I am going to donate some money to the campaign of whomever runs against you in your next election. I am sending this same message to ALL the committee members. You have individually and collectively failed the citizens of the USA. You are not an effective politician. You should no longer continue to represent hard working citizens.
[Message ends]

Sen. Patty Murray (D-WA), (co-chair) Secretary of the Democratic Conference; Chairwoman of the Democratic Senate Campaign Committee
Sen. Max Baucus (D-MT), Chairman of the Senate Finance Committee; Vice Chairman of the Joint Committee on Taxation
Sen. John Kerry (D-MA), Chairman of the Senate Foreign Relations Committee
(D-MT), Chairman of the Senate Finance Committee; Vice Chairman of the Joint Committee on Taxation
Sen. Jon Kyl (R-AZ), Senate Minority Whip
Sen. Rob Portman (R-OH)
Sen. Pat Toomey (R-PA)
Rep. Jeb Hensarling (R-TX), (co-chair) Republican Conference Chairman SHAME: Does not accept email outside of 5th Congressional District of Texas.
Rep. Dave Camp (R-MI), Chairman of the House Ways and Means Committee; Chairman of the Joint Committee on Taxation SHAME: Does not accept email outside of his district.
Rep. Fred Upton (R-MI), Chairman of the House Energy and Commerce Committee SHAME: His weblink contact creates this alert "This Connection is Untrusted"
Rep. James Clyburn (D-SC), Assistant Democratic Leader SHAME: Does not accept email outside of his district.
Rep. Xavier Becerra (D-CA), Democratic Caucus Vice Chair SHAME: Does not accept email outside of his district.
Rep. Chris Van Hollen (D-MD), House Budget Committee ranking member SHAME: Does not accept email outside of his district.

NOTE: The House of Representatives' server will not deliver my email message. Anyone in a "qualifying" HoR district is encouraged to forward this posting to them. Thank you.

Brushless Motor vs Brushed Motor

A DC Brushless Motor uses a permanent magnet external rotor, three phases of driving coils, one or more Hall effect devices to sense the position of the rotor, and the associated drive electronics. The coils are activated, one phase after the other, by the drive electronics as cued by the signals from the Hall effect sensors, they act as three-phase synchronous motors containing their own variable frequency drive electronics.

Electronic commutation based on Hall position sensors
Less required maintenance due to absence of brushes
Speed/Torque- flat, enables operation at all speeds with rated load
High efficiency, no voltage drop across brushes
High output power/frame size.
Reduced size due to superior thermal characteristics. Because BLDC has the windings on the stator, which is connected to the case, the heat dissipation is better
Higher speed range - no mechanical limitation imposed by brushes/commutator
Low electric noise generation

Higher cost of construction
Control is complex and expensive
Electric Controller is required to keep the motor running. It offers double the price of the motor.

- - - - - - - - - - - - - -

A Brushed Motor has a rotating set of wound wire coils called an armature which acts as an electromagnet with two poles. A mechanical rotary switch called a commutator reverses the direction of the electric current twice every cycle, to flow through the armature so that the poles of the electromagnet push and pull against the permanent magnets on the outside of the motor. As the poles of the armature electromagnet pass the poles of the permanent magnets, the commutator reverses the polarity of the armature electromagnet. During the instant of switching polarity, inertia keeps the classical motor going in the proper direction.

PRO Brushed Motor
Two wire control
Replaceable brushes for extended life
Low cost of construction
Simple and inexpensive control
No controller is required for fixed speeds
Operates in extreme environments due to lack of electronics

CON Brushed Motor
Periodic maintenance is required
Speed/torque is moderately flat. At higher speeds, brush friction increases, thus reducing useful torque
Poor heat dissipation due to internal rotor construction
Higher rotor inertia which limits the dynamic characteristics
Lower speed range due to mechanical limitations on the brushes
Brush Arcing will generate noise causing EMI

Click on images for their source and catalog.
Text source

Thursday, November 03, 2011

Death Is My Caddy

Death is my caddy and the others
   in my party don't seem to notice.
He proposes the seven iron
   as I play under par.
While I get no holes-in-one,
   Death applauds my long putts.
I can feel Death's hot eyes
   as I wedge out of a sand trap.
Death chuckles when I
   murder the ball.
Death kindly offers advise
   on how I can improve my swing.
I fish some other's lost
   Titleist from the water hazard.
Lightning strikes me down
   as I tee off on the 13th hole.
I will wait for my companions
   at Gabriel's clubhouse bar.

Death Is My Caddy
by Steve Bull, November 2, 2011
for Bert Fraser
Death and Dying Conference
sponsored by AtlantiCare
at Stockton College